The mulching attachment for the 42-in. mower provides excellent performance. This is a high-performance mulching attachment that includes a mulch plug and special mulching blades.
Remember you will have to follow the 1/3rd rule. No more than 1/3 of the grass blade should be cut off at one time. This allows more efficient mulching and will promote the continued good health of the grass. If the desired cut height can't be achieved by cutting off 1/3, or there is clumping of the clippings, it may be required to cut higher; wait a day, then lower the mower and make a second pass. Mow at proper intervals approximately every 4 to 5 days.
This 42C mulching kit is compatible on the following models with 42C decks that have two blades.
SST15 With C deck Not the AP ( All-Purpose ) Deck